Pre-osteoporosis is claimed to affect more than half of all white postmenopausal women and Moynihan describe attempts to marketing drugs to these relatively healthy women as a case of "disease-mongering".

Evidence under question

Moynihan and colleagues say the evidence used by the drug companies to justify their latest marketing move exaggerated the benefits of the drugs and downplayed the risks.

It was based on four reanalyses of osteoporosis drug trials. The reanalyses were designed to investigate the benefits of these drugs for women with pre-osteoporosis.

Moynihan and colleagues examined the reanalyses of the original drug trials and found they overstated the benefits of the drugs by quoting a "relative risk reduction".

In the reanalysis of the drug Raloxifene, for example, authors cite a 75% reduction in relative risk, although this translates into only a 0.9% reduction in absolute risk, say Moynihan and colleagues.

"In other words, up to 270 women with pre-osteoporosis might need to be treated with drugs for three years so that one of them could avoid a single vertebral fracture," they say.

Most of the published reanalyses also played down the harmful side effects of the drugs, say Moynihan and team.

For example, they say the reanalysis of the drug Alendronate did not discuss the side effects which include serious gastrointestinal problems and in rare cases, osteonecrosis - or bone death - of the jaw.

Conflicts of interest

Moynihan and team highlight what they say are potential conflicts of interest in the publication of the drug studies.

All the original drug trials were funded by the drug companies and in three of four reanalyses, drug company employees were part of the investigating team, they say.

The World Health Organization is now developing guidelines on how to treat and deal with women diagnosed with pre-osteoporosis.

"Whether this advice will stop industry efforts to encourage treatment in low-risk women is questionable," say Moyhihan and colleagues.

Over-treatment 'not an issue in Australia'

Australian osteoporosis expert, Professor Philip Sambrook, says while he agrees with some of the points raised by Moynihan and colleagues he believes over-treatment is not an issue in Australia.